1. Field of the Invention
The present invention relates to a display filter, a display device including the display filter, and a method of manufacturing the display filter. More particularly, the present invention relates to a display filter that enhances contrast of a display device viewed in a bright room, a display device including the display filter, and a method of manufacturing the display filter.
2. Description of the Related Art
As modern society becomes more information-oriented, the technology of photoelectronic devices and apparatuses is advancing, and these devices are becoming widespread. In particular, image display devices are in widespread use in devices such as TV screens and PC monitors. Thinly built wide screens have become mainstream display devices.
In particular, a plasma display panel (PDP) is gaining popularity as a next-generation display device to replace a cathode ray tube (CRT) because it is thin, has a large screen, and can be readily fabricated. A PDP device displays images based on a gas discharge phenomenon, and exhibits superior display characteristics, e.g., a high display capacity, high brightness and contrast, free from after-image, and a wide viewing angle.
In a PDP device, when a direct current (DC) or alternating current (AC) voltage is applied to electrodes, a gas plasma discharge occurs that produces ultraviolet (UV) light. The UV emission excites adjacent phosphors to emit visible light.
Despite the above advantages, PDPs have several problems associated with driving characteristics, including an increase in electromagnetic (EM) radiation, near-infrared (NIR) emission, phosphor surface reflection, and an obscured color purity due to orange light emitted from helium (He) or xenon (Xe) that is used as a sealing gas.
The EM radiation generated by PDPs may adversely affect humans and cause electronic devices, e.g., wireless telephones or remote controls, to malfunction. Thus, in order to use such PDPs, there is a need to reduce the EM radiation emitted from the PDPs to a predetermined level or less, e.g., by shielding. Various PDP filters have been used for such shielding, as well as to reduce unwanted reflections and to enhance color purity. For example, various PDP filters having an EM shielding function, a NIR wave shielding function, an antireflection (AR) function, and a color purity enhancing function, can be used with PDPs.
Conventional PDP filters include an adhesive layer and a conductive metal layer. The adhesive layer is a transparent film having EM shielding properties, good adhesion, fluidity in predetermined conditions, and exhibiting a screening effect. The conductive metal layer is a film that is geometrically patterned by microlithography and has an aperture ratio exceeding 50%.
However, conventional PDP filters cannot prevent external light from entering a panel assembly, leading to reduction in contrast in bright viewing conditions. This external light may interfere with light emitted from a discharge cell in the panel assembly, thereby lowering contrast, ultimately degrading the image displayed on the PDPs.